Four corn. fire-retarding agents were used for impregnation of oak samples studied for heat release rate and CO, CO2 and smoke (soot) emissions by cone calorimetry. The expt. data were used for computer simulation of temp. distribution, upper layer of smoke and visibility redn. in a room-corridor system. A complex zone model-based computer program was used for the simulation. One of the studied fire-retarding agents did not prevent the wood samples against the fire but even accelerated the combustion rate and smoke emission.